I'm following a recipe from the Artisan Bread in Five Minutes a Day book and want to bake two loaves at the same time. For one loaf, you are supposed to add one cup of water to a container in the oven, which steams the bread while baking. If baking two loaves, do I have to increase the amount of water or should one cup be enough?
The water is used to create steam used to promote crust on the surface of the bread. The only reason you would need to increase the water for steam would be if you started using a larger oven.
I have done this a few times already. You may need to adjust baking times slightly. But otherwise it works just as they say. Just make sure you have enough room on your stone.